File 0001-Fix-CMAKE_MODULE_PATH-breakage-due-to-find_dependenc.patch of Package ceres-solver

From 8fc2ccb9ead8dd57b92049313ec9577133e607b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20Br=C3=BCns?= <stefan.bruens@rwth-aachen.de>
Date: Fri, 22 Nov 2024 06:26:45 +0100
Subject: [PATCH] Fix CMAKE_MODULE_PATH breakage due to find_dependency

The `find_dependency(...)` macro uses `return()` on failure, and the
calling code fails to restore the CMAKE_MODULE_PATH then.

Wrap the call in a `function()`, and handle failures from there.

Fixes #1122.
---
 CMakeLists.txt                |  4 ++--
 cmake/CeresConfig.cmake.in    | 24 +++++++++++++++++-------
 internal/ceres/CMakeLists.txt |  2 +-
 3 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8e49c19..dfdf8eb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -295,7 +295,7 @@ if (SUITESPARSE)
   find_package(SuiteSparse 4.5.6 COMPONENTS CHOLMOD SPQR
     OPTIONAL_COMPONENTS Partition)
   if (SuiteSparse_FOUND)
-    set(SuiteSparse_DEPENDENCY "find_dependency(SuiteSparse ${SuiteSparse_VERSION})")
+    set(SuiteSparse_DEPENDENCY "_ceres_find_dep_wrapper(SuiteSparse ${SuiteSparse_VERSION})")
     # By default, if all of SuiteSparse's dependencies are found, Ceres is
     # built with SuiteSparse support.
     message("-- Found SuiteSparse ${SuiteSparse_VERSION}, "
@@ -329,7 +329,7 @@ if (EIGENMETIS)
     # link-only METIS::METIS target to avoid undefined linker errors in projects
     # relying on Ceres. We do not actually need to propagate anything besides
     # the link libraries (such as include directories.)
-    set(METIS_DEPENDENCY "find_dependency(METIS ${METIS_VERSION})")
+    set(METIS_DEPENDENCY "_ceres_find_dep_wrapper(METIS ${METIS_VERSION})")
     # METIS find module must be installed unless a package config is being used.
     if (NOT METIS_DIR)
       install(FILES ${Ceres_SOURCE_DIR}/cmake/FindMETIS.cmake
diff --git a/cmake/CeresConfig.cmake.in b/cmake/CeresConfig.cmake.in
index ceb7e26..5e258d5 100644
--- a/cmake/CeresConfig.cmake.in
+++ b/cmake/CeresConfig.cmake.in
@@ -79,14 +79,10 @@ macro(CERES_REPORT_NOT_FOUND REASON_MSG)
 
   # Note <package>_FIND_[REQUIRED/QUIETLY] variables defined by
   # FindPackage() use the camelcase library name, not uppercase.
-  if (Ceres_FIND_QUIETLY)
-    message(STATUS "Failed to find Ceres - " ${REASON_MSG} ${ARGN})
-  elseif (Ceres_FIND_REQUIRED)
+  if (Ceres_FIND_REQUIRED)
     message(FATAL_ERROR "Failed to find Ceres - " ${REASON_MSG} ${ARGN})
-  else()
-    # Neither QUIETLY nor REQUIRED, use SEND_ERROR which emits an error
-    # that prevents generation, but continues configuration.
-    message(SEND_ERROR "Failed to find Ceres - " ${REASON_MSG} ${ARGN})
+  elseif (NOT Ceres_FIND_QUIETLY)
+    message(STATUS "Failed to find Ceres - " ${REASON_MSG} ${ARGN})
   endif ()
   return()
 endmacro(CERES_REPORT_NOT_FOUND)
@@ -177,6 +173,20 @@ set(CERES_VERSION @CERES_VERSION@)
 
 include(CMakeFindDependencyMacro)
 # Optional dependencies
+macro(_ceres_find_dep_wrapper)
+  function(_ceres_find_dep_wrapper_wrapper)
+    find_dependency(${ARGN})
+    set(${ARGV0}_FOUND TRUE PARENT_SCOPE)
+    return()
+  endfunction()
+  _ceres_find_dep_wrapper_wrapper(${ARGN})
+  if (NOT ${ARGV0}_FOUND)
+    CERES_REPORT_NOT_FOUND("${ARGV0} not found")
+  elseif (NOT Ceres_FIND_QUIETLY)
+    message(STATUS "Found ${ARGV0}")
+  endif()
+endmacro()
+
 @METIS_DEPENDENCY@
 @SuiteSparse_DEPENDENCY@
 @CUDAToolkit_DEPENDENCY@
diff --git a/internal/ceres/CMakeLists.txt b/internal/ceres/CMakeLists.txt
index f9fc241..9ff6469 100644
--- a/internal/ceres/CMakeLists.txt
+++ b/internal/ceres/CMakeLists.txt
@@ -35,7 +35,7 @@
 find_package(Threads REQUIRED)
 list(APPEND CERES_LIBRARY_PRIVATE_DEPENDENCIES Threads::Threads)
 # Make dependency visible to the parent CMakeLists.txt
-set(Threads_DEPENDENCY "find_dependency (Threads)" PARENT_SCOPE)
+set(Threads_DEPENDENCY "_ceres_find_dep_wrapper(Threads)" PARENT_SCOPE)
 
 # Source files that contain public symbols and live in the ceres namespaces.
 # Such symbols are expected to be marked with CERES_EXPORT and the files below
-- 
2.47.0